Question

What is the need for measurement of physical quantities?

Answer 1

we need to measure physical quantities to know their mass

Answer 2

physical quantity is defined as a property of a body/object/substance that can be quantified(valuating) by measurement.
why v need this physical measurement is to have a universal standard set of values eg 1kg is 1000 g / 1 liter is 1000ml
 there are 2 type of quantities 1\ extensive quantity 2\intensive quantity